To correctly separate a corporate name from a personal name, even when the corporate name is mixed with the personal name in one code.

A name character string is divided into words to decide the presence of the word expressing a representative case in the name character string, the character string of a portion in a front side of the representative case is subjected to corporate name analysis when the representative case exists in the name character string, the character string of a portion in a rear side of the representative case is subjected to personal name analysis, the character string is subjected to personal name analysis when no representative case exists in the name character string, the corporate name is settled as a result of the corporate name analysis when not settled to the personal name, the personal name analysis is carried out by two words when the two terminal words mean a surname and a personal name, results of the corporate name analysis and the personal name analysis are expressed as points using a personal/corporate determination rule when not settled to the corporate name, and the propriety of the personal name or the corporate name is determined finally by the points.